This invention relates in general to vehicle headliners and in particular to a blow formed air duct and other blow formed components that are attached to a vehicle headliner.
In modern vehicles, headliners are typically placed against the inside surface of the top of the passenger compartment to provide a covering. More recently, and in particular in larger vehicles such as minivans, air flow vents are mounted through the headliner to deliver air into the passenger compartment. Typically, air flow ducts have been provided between the ceiling of the vehicle and the headliner to direct air flow from the vehicle air flow circulation system through to vents formed through the headliner of the vehicle.
Referring now to the drawings, there is illustrated in FIG. 1 a known headliner assembly 20 that includes a headliner body 22 with a non-exposed, upper face 23 and an exposed, lower face 25 having vent openings 24 and 26 spaced along one lateral side. Similar openings, which are not shown, also are spaced along the opposite lateral side of the headliner body 22. An air supply opening 28 communicates with an air supply vent in the frame of the vehicle. A U-shaped plastic air duct 30 is positioned on the upper headliner face 23 and along a side of the headliner body 22 to define the air flow passages. An enlarged vent portion 32 is positioned over the vent opening 24 and an enlarged vent portion 34 covers vent opening 26. Another vent side portion 36 is positioned along the opposite side of the headliner body 22. A rear connection portion 38 connects the two side portions 32 and 36 to provide the generally U-shaped duct 30. Vents 40 are placed within the openings 24 and 26 to complete the assembly 20.
The air duct 30 is typically formed from a plastic by injection or vacuum molding. The air duct 30 is secured to the headliner body 22 by adhesive or welding techniques, such as vibration, sonic or dielectric wielding.
As shown in FIG. 2, the air duct 30 is open at its lower face and the upper face 23 of the headliner body 22 closes off an airflow passage 42 in combination with the duct 30. In this way, air can pass from opening 28 such as from a supply duct 44 formed in the frame of the vehicle body and into the airflow passage 42. From airflow passage 42, air flows to the vent openings 24 and 26 on both lateral sides of the vehicle. Further details of the air duct 30 are included in U.S. Pat. No. 6,062,635, which issued on May 16, 2000, and is incorporated herein by reference.
The air duct 30 described above requires a continuous seal between the edges of duct portions 32, 36 and 38 and the surface 23 of the headliner body 22 to form the airflow passage 42. If the seal is intermediate, air will leak from the duct 30 and into the space between headliner body 22 and the roof of the passenger compartment. Such leaks would decrease the air flow through the vents and thereby reduce the efficiency of the vehicle heating and air conditioning system. Additionally, the increased air pressure between the headliner body 22 and the roof of the vehicle may separate the headliner from the vehicle roof. Accordingly, it would be desirable to provide an improved air duct.
This invention relates to blow formed air duct and other blow formed components that are attached to a vehicle headliner.
The present invention contemplates a vehicle headliner assembly that includes a formed headliner body having at least one aperture formed threthrough. A seamless tubular air duct is attached to the headliner body. The air duct has at least one aperture formed therethrough that is aligned with the aperture formed through the headliner body. The seamless duct is formed by a blow molding process and can include a plurality of seamless tubular portions that are joined together to form the complete duct. The air duct also can be formed to include attachment points for other components, such as, for example, hand grab assist handles and wiring harness attachment devices. Thus, the blow molded components can provide multiple functions.
The invention also contemplates a process for forming a vehicle headliner assembly that includes providing a hollow tubular blank formed from plastic, the blank having a closed end and an open end opposite from the closed end. The blank is heated until it becomes. The heated blank is placed into a hollow mold and a pressurized gas is supplied into the open end of the blank to expand the blank to conform to the shape of the mold cavity to form a component for a headliner assembly. The headliner component is allowed to cool and then removed from the mold. Finally, the headliner component is attached to a headliner body.
Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.